Archive for April, 2007

Presenter: Andy Tucker, Principle Engineer, VMware.

Nothing shockingly new to report here – but to watch out that the LUN numbers presented to the VCB proxy must match the ESX hosts LUN numbers. Additionally, VCB does not currently support multiple fibre-channel cards for multipathing to the LUN.

Andy did outline some new features planned for VCB including:

• Solve the LUN numbering problem by using the VMFS UUID values held in the metadata
• Multipaths to be supported
• Using VMware Convertor assist moving files from the VCB proxy to the ESX host
• Increamental Backups
• Better quiescing of the VM during the snapshot process

Later this week I did a lab on VCB. One neat trick was that the lab guys had set up the VCB proxy to also be a NAS/NFS to the ESX host. So we restored the backup to the VCB proxy into a folder that had been set a mount point to the ESX host. This made the network restore process with vcbrestore much easier to achieve.

New options to license desktop virtualization and diskless PCs give Windows Vista Enterprise customers more choices, says the director of Microsoft’s Windows Business Group.

Link:

http://www.microsoft.com/presspass/features/2007/apr07/04-02WVenterprise.mspx

In the afternoon I attended the session from Equalogic. In case you don’t know they are iSCSI SAN provider who bundle a lot of “virtual storage” functionality in their product. The finer detail of the offering went over my head. I wouldn’t regard myself as a storage specialist – and in part that’s why I chose to attend. I’ve heard very interesting things about this company. Very fast, very efficient, very cost-effective. There seems to be an inherent slowness to take on new technology around the field storage. This is understandable considering its about your most important stuff – your data. Additionally, if you have spent millions of £$€ on a SAN, a new storage offering doesn’t seem horribly appealing. But for new customers without an existing storage infrastructure these companies are interesting. 

I followed up that session by attending a VDI Overview presented by Richard Garsthagen, Product Marketing Manager for VMware in EMEA, and also organiser of TSX. I regard myself as a VDI sceptic, coming from a bias of Citrix background. This year I did not renew my Citrix instructor certification as I want to dedicate my time to virtualisation for which I am better known (and better paid!!!).  So I’m coming at this with new eyes. Still I feel there are couple of major problems remain with all the VDI “offerings”. Firstly, you have cobble together a couple of solutions together to deliver a desktop – virtualisation layer, broker layer, SSL layer and a desktop device for the user to sit at. Secondly, regardless of how great VirtualCenter is – it is not geared up to create hundreds of desktops quickly. Sure VMware LabManager could do that – but at what cost? Thirdly, I worry about the storage issue of 150 virtual disks on my expensive SAN storage. Clearly, some kind of “master” vmdk with snapshots for each of our users is the way forward (and LabManage can do that today) this would keep the storage costs down, and help with patch management as one VMDK means on level of software and OS patching. 

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Presenter: Darren Brunett

Firstly, you might ask where Part I was – as part II came first on the list of options in the schedule. Joking apart this was a good session – not least because rtfm-ed.co.uk was mentioned in the powerpoint slides!  I met Darren at the London User Group briefly where have gave presentations on VMFS and other troubleshooting issues. He’s an easy going guy with a great self-depreciating presentation style. Darren ran through some of the top support issues he deals with in his role as a Senior Technical Support Engineer at VMware. These sessions always interest me – because frequently students bring the very same problem to me either during courses, or afterwards informally via email. Darren covered a lot of ground – but a couple of points he made me reach for my pen and pad to scribble them down.

Firstly, he covered recovering lost VMFS partitions caused people having a “Homer Simpson” moment. Generally, if some removes a VMFS volumes, and then repartitions that LUN for another purposes your chances of recovery are slim. If however, someone removes a VMFS, and then has left the LUN untouched there is a good chance of recovering the VMFS. Very simply its possible to put the partition table information back in place using fdisk. You do need to use esxcfg-vmhbadevs to find out the Linux /dev/sdN value. But after that it is a case of putting the primary partition back on the disks. Expert mode is used to make sure the disk is offset for the disk alignment automatically implemented by the Vi Client. Anyway, I was very much taken by the process – so I plan to be Homer Simpson soon and give Darren’s steps a roadtest.

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Presenter: Thorbjorn Donbaek (Senior Storage Developer, VMware)

This session was all about tweaking storage settings – especially in the area of analysing VM driver queues, vmkernel disk queues and fibre-channel queues. It was my first session of the day and it was a bit of struggle to keep up. I got the impression it was the speakers first session of the day and some of the finer detail went over my head. Perhaps that says more about my good my storage knowledge is. Anyway, I got some tips and tricks such as: 

• Some older distros of Linux work better with the BusLogic driver. In general LSIlogic is preferred for Windows
• There as some useful KB articles which discuss the possible benefits of adjusting queue lengths of Qlogic (KB 1269) and Emulex cards (KB 8535211)
• The vmkfstools command options of -I are still preferred for moving large files around as it still reduces the SCSI reservations required for disk transactions. Unlike commands like CP which handle file creation less efficientally. 
• Physical Compatibility RDMs can cause problems in RDMs. This is because the VM places a SCSI reservation on the device (such as a tape device) using the WWN of the original host. When the VM is moved via VMotion, these reservations remain tied to the original hosts WWN value. RDMs with virtual compatibility remain unaffected. 

Later the preset went on to discuss some issues with VMware iSCSI Software Initiator. Most of this was familiar ground for me. Except for one issue I’d never come across. The NICs used behind a VMkernel port group for iSCSI must be in the same V/LAN – or broadcast domain. This can lead to single point of failure on the physical switch. I’m not sure how much of show stopper this is. Most Cisco configurations I see have the second switch up-linked by a passive connection the primary switch anyway. But perhaps one to watch out for…?

TSX opened to day at the Acropolis. The venue is fine, if somewhat circa 1970′s, and I think delegates will miss the roller-coasters of Paris, Disney. This said, this year we are more upmarket bunch strolling our way along the strip of Nice. In the morning we had the customary key notes sessions. Nothing spectacular to report about these events – virtualisation rocks, virtual appliances rock, the hardware in future will rock, and VMware will be there to take advantage of it. Oh, and open-source community initiatives counts such as virtual disk formats and so on. On the community side of things Robert Dell’Immagine gave us a run down on how the VMTN will improve in months to come. With a Wiki project, better profiles and kind of LinkedIn but for the forums. I hope to contribute to the Wiki project by “seeding” it with content from my free online guides – and then letting the community edit and improve that content as systems change. 

My TSX began with a trainer event on the Monday before TSX official opened. It was an opportunity to meet up with my fellow instructors and to be given the inside track on VMware Educations plans for the future. So here’s some news. Firstly, the new “Deploy, Secure and Analyse” (DSA)course can be taken, and will count towards your VCP status. So for people who feel the “Install and Configure” (I&C) course is inappropriate they can do the DSA course instead and still be certified. However, the exam questions will still be closely related to the I&C content. In the US VMware plan to have a “test” make sure that the right people are allowed to the attend the DSA course – but there no plans for the European arm of VMware Education – the VATC programme to be forced to take a “pre-requisite” test.